AbstractObjectiveThe aim is to define clinical and histologic characteristics of peri‐implant tissues in health and describe the mucosa–implant interface.ImportanceAn understanding of the characteristics of healthy peri‐implant tissues facilitates the recognition of disease (i.e., departure from health).FindingsThe healthy peri‐implant mucosa is, at the microscopic level, comprised of a core of connective tissue covered by either a keratinized (masticatory mucosa) or non‐keratinized epithelium (lining mucosa). The peri‐implant mucosa averages about 3 to 4 mm high, and presents with an epithelium (about 2 mm long) facing the implant surface. Small clusters of inflammatory cells are usually present in the connective tissue lateral to the barrier epithelium. Most of the intrabony part of the implant appears to be in contact with mineralized bone (about 60%), while the remaining portion faces bone marrow, vascular structures, or fibrous tissue. During healing following implant installation, bone modeling occurs that may result in some reduction of the marginal bone level.ConclusionsThe characteristics of the peri‐implant tissues in health are properly identified in the literature, including tissue dimensions and composition. Deviation from the features of health may be used by the clinician (and researcher) to identify disease, including peri‐implant mucositis and peri‐implantitis.